Fionna is a distinctive girls' name in United States, ranking #7501 in 2007 with 17 recorded births. The name reached its all-time peak in 2012 with 41 births ranking #3804. Since 1996, the popularity has increased by 41.7%. In 2007, approximately 1 in every 113,085 girls born was named Fionna. FALLING Recent data shows the name is currently falling.